How do I fix this error?

1 次查看（过去 30 天）
Byungho
Byungho 2024-4-4
评论： Walter Roberson 2024-8-25
Ran in:
deltat=0.1;
nsamples=2^10;
fs=1/deltat;
time=[0 : deltat : deltat*(nsamples-1)];
psdtot(1:nsamples/2+1) = zeros(1,nsamples/2+1);
nblock = 10;
for k=1:nblock
for i=1: nsamples
ydata(i,:) =5+10*cos(2*pi*time+pi/6)+15* randn(1);
end
[pxx,f] = periodogram(ydata,rectwin(nsamples),nsamples,fs);
size(psdtot)
size(pxx)
psdtot = psdtot + pxx/nblock;
end
ans = 1x2
1 513
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
ans = 1x2
513 1024
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
Arrays have incompatible sizes for this operation.
figure(1);
plot(time,ydata);
I'm trying to generate Gaussian noise from x(t)=5+10*cos(2*pi*t+pi/6)+G(sigma,t)
G(sigma,t) is Gaussian noise with a standard deviation of 15 (sigma G=15), detat=0.1(s), and nsample=2^10.
It is the start of calculating Power Spectral Density with FFT.
The overall variance of the signal is (sigma g)^2+(A)^2/2 as expected.
The generated random signal should be sinusoidal because X(t) has the cosine factor.
  1 个评论
Torsten
Torsten 2024-4-4
You cannot add arrays of size 1x513 and 513x1024 (see above).

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

cui,xingxing
cui,xingxing 2024-4-5
编辑：cui,xingxing 2024-4-27
Ran in:
You should make sure that the array dimensions in the arithmetic are consistent, for example I changed your psdtot variable to a column vector. As far as I remember, matlab supports automatic dimension expansion since R2016a/b.
deltat=0.1;
nsamples=2^10;
fs=1/deltat;
time=[0 : deltat : deltat*(nsamples-1)];
psdtot(1:nsamples/2+1) = zeros(1,nsamples/2+1);
psdtot = psdtot(:); % here
nblock = 10;
for k=1:nblock
for i=1: nsamples
ydata(i,:) =5+10*cos(2*pi*time+pi/6)+15* randn(1);
end
[pxx,f] = periodogram(ydata,rectwin(nsamples),nsamples,fs);
psdtot = psdtot + pxx/nblock;
end
figure(1);
plot(time,ydata);
-------------------------Off-topic interlude, 2024-------------------------------
I am currently looking for a job in the field of CV algorithm development, based in Shenzhen, Guangdong, China. I would be very grateful if anyone is willing to offer me a job or make a recommendation. My preliminary resume can be found at: https://cuixing158.github.io/about/ . Thank you!
Email: cuixingxing150@gmail.com
  1 个评论
Derek
Derek 2024-4-9
编辑：Derek 2024-4-9
So using this data provided how do you plot the psd vs frequency? In a log log plot. Do you have to do the fgts prior to the peridogram

请先登录，再进行评论。

更多回答（1 个）

Jose Sevilla
Jose Sevilla 2024-8-25
Ran in:
Hola todos necesito ayuda con este gramento de codigo en Matlab 2024RA
% Inicialización de variables
distances = distance_start:distance_increment:distance_end;
Unrecognized function or variable 'distance_start'.
received_power_5 = zeros(1, num_measurements); % 5to piso
received_power_4 = zeros(1, num_measurements); % 4to piso
received_power_3 = zeros(1, num_measurements); % 3er piso
std_dev_5 = zeros(1, num_measurements); % Desviación estándar 5to piso
std_dev_4 = zeros(1, num_measurements); % Desviación estándar 4to piso
std_dev_3 = zeros(1, num_measurements); % Desviación estándar 3er piso
rmse = zeros(1, num_measurements); % Error medio cuadrático
k_factor = zeros(1, num_measurements); % Factor K
  1 个评论
Walter Roberson
Walter Roberson 2024-8-25
That code has the potential to work provided that
num_measurements = length(distances);
But if num_measurements is different than distances, then it seems most likely that you need more like
% Inicialización de variables
distances = (distance_start:distance_increment:distance_end).';
num_distances = length(distances);
received_power_5 = zeros(num_distances, num_measurements); % 5to piso
received_power_4 = zeros(num_distances, num_measurements); % 4to piso
received_power_3 = zeros(num_distances, num_measurements); % 3er piso
std_dev_5 = zeros(num_distances, num_measurements); % Desviación estándar 5to piso
std_dev_4 = zeros(num_distances, num_measurements); % Desviación estándar 4to piso
std_dev_3 = zeros(num_distances, num_measurements); % Desviación estándar 3er piso
rmse = zeros(num_distances, num_measurements); % Error medio cuadrático
k_factor = zeros(num_distances, num_measurements); % Factor K

请先登录，再进行评论。

类别

在 Help Center 和 File Exchange 中查找有关 Correlation and Convolution 的更多信息

标签

产品


版本

R2023b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by